The invention relates to an arrangement for an electronic component which is operable at low temperatures and consists of a housing for the component and a cooler which is in communication with the housing and operates in accordance with the Joule-Thomson effect.
Electronic miniature components which reach their optimum electric characteristic data only at temperatures below room temperature are required for many uses. Examples thereof are semiconductor detectors made of mercury-cadmium-telluride or of lead-tin-telluride which reach their optimum light sensitivity only at approximately 80 degrees Kelvin. Twin-walled, evacuated housings with a radiation transmitting window above the semiconductor component are frequently used for such semiconductor components. If extremely brief cooling times and moderate operating periods are required it is possible to use housings which are not evacuated. In this case the cooler required for cooling down the electronic component preferably operates in accordance with the Joule-Thomson principle and is of cylindrical or conical shape, with different cone angles being feasible.
According to the Joule-Thomson effect, a suitable gas, for example, air, argon or nitrogen, cools off when it exits from a nozzle opening under high pressure and expands. The gas cooling down during expansion is preferably conducted away at a suitably placed capillary through which the gas is directed towards the nozzle opening, so that the gas which is guided inside the capillary is pre-cooled. The capillary preferably consists of a pipe coil arranged on a cylindrical or conical carrier member.
There should be a close contact between the aforementioned pipe coil and the adjacent housing wall for the electronic component to ensure that the return flow of the expanded gas also moves along a spiral-shaped path, and an effective heat exchange occurs between the cooled returning gas and the gas supplied under high pressure.
The spiral-shaped flow of the returning gas can, however, only be achieved if there is good sealing between the pipe coil and the adjacent outside wall of the housing for the electronic component. This, in turn, makes good thermal contact with the housing for the electronic component unavoidable, which causes a reduction in the pre-cooling of the gas supplied and interference in the optimum temperature profile along the capillary. As a consequence, the cooling of the electronic component is slowed down in an undesired manner.